I am 59 years old and I am 4 years post op from robotic surgery and I was very lucky in that I had no ED problems after surgery from the day the catheter was removed. I had no problem getting rock solid erections, BUT!!!! ..... only with constant manual stimulation. With continual manual stimulation, I could get and maintain an erection for as long as the stimulation continued. Without the manual stimulation, the erection went flat in seconds.
Prior to surgery, just looking at a naked woman was enough to get a solid erection, but after surgery, I could think about sex and look at naked women 24/7 and feel absolutely nothing down there, not even a tingle, but as soon as the manual stimulation started, then I so did the erection.
Then about two years post op, I noticed that when I looked at a naked woman, I started to actually feel a partial erection start from just the thoughts alone, without any manual stimuli. Now at four years post op, I wake up almost every morning with a solid erection, and now I can also get about 50% erection from just thinking about sex and looking at a naked woman without any manual stimuli. I guess from this you can conclud that nerves do heal and reconnect over time.